Overview and status of a mirror fusion propulsion system design study

The main goal of this paper is to describe and emphasize the important discoveries made since 1986 in the engineering design of space fusion propulsion plants.

Among the important discoveries are four fundamental design principles (DPs) which should be used when adapting candidate Earth-based fusion-electric power plants to propulsion in space.

1. DP1. Maximize direct access to space for waste radiation.

2. DP2. Operate components as passive radiators whenever possible.

3. DP3. Optimize the plasma characteristics for best specific jet power

4. DP4. Optimize mission capability versus lifetime-mass-to-orbit (LMTO).

Another discovery is a design philosophy called IDEAs (Integrated Design Environment Algorithms) which is a tool for discovering new fundamental design principles.

These discoveries allowed us to adapt, and then to optimize, an earth-based fusion-electric magnetic-mirror-fusion reactor concept for propulsion in space. The resulting design is called the Mirror Fusion Propulsion System (MFPS); and its design status is reviewed.

This work can be used as a general road map for others attempting to convert earth-based designs to propulsion in space. It also has applicability to matter-antimatter propulsion systems engineering.     

How far – if at all – should the USA cooperate with China in space?

China has engaged in a steady, long-standing effort to build and strengthen its space capabilities, achieving progressively more ambitious milestones and staking its claim as a major space power. It is also increasingly engaging in cooperative efforts. A number of issues must be weighed, however, before the USA should consider any collaboration with it. These include the essentially military nature of China’s space program, the fact that China’s intentions in space and decision-making process are far from ‘transparent’, and the way it uses its space activities to pursue foreign policy goals. While the latter could be useful in, e.g., reducing tensions on the Korean peninsular through a space-services-for-giving-up-missiles tradeoff, and while there is scope for collaboration in space science missions, there are no compelling reasons for the USA to pursue cooperation in human spaceflight with China.     

一种节油的柔性变形机翼

最近美国柔性系统公司在缩比复合材料公司的"白色骑士"飞行试验台上,完成了一项"自适应柔性机翼"技术的飞行试验。这项研制工作得到了美国空军研究实验室的支持,此前已经成功地完成了风洞试验。这种采用层流翼型的自适应柔性机翼被垂直地安装在"白色骑士"飞机的挂架上,分别在8000米和13000米高度上进行了7次飞行试验,累计飞行20小时。装在飞机尾部下方的摄像机可以使机组人员检验试     

The Burst Alert Telescope (BAT) on the SWIFT Midex Mission

he burst alert telescope (BAT) is one of three instruments on the Swift MIDEX spacecraft to study gamma-ray bursts (GRBs). The BAT first detects the GRB and localizes the burst direction to an accuracy of 1–4 arcmin within 20 s after the start of the event. The GRB trigger initiates an autonomous spacecraft slew to point the two narrow field-of-view (FOV) instruments at the burst location within 20–70 s so to make follow-up X-ray and optical observations. The BAT is a wide-FOV, coded-aperture instrument with a CdZnTe detector plane. The detector plane is composed of 32,768 pieces of CdZnTe (4×4×2 mm), and the coded-aperture mask is composed of ∼52,000 pieces of lead (5×5×1 mm) with a 1-m separation between mask and detector plane. The BAT operates over the 15–150 keV energy range with ∼7 keV resolution, a sensitivity of ∼10⁻⁸ erg s⁻¹ cm⁻², and a 1.4 sr (half-coded) FOV. We expect to detect > 100 GRBs/year for a 2-year mission. The BAT also performs an all-sky hard X-ray survey with a sensitivity of ∼2 m Crab (systematic limit) and it serves as a hard X-ray transient monitor.     

Error Reduction in HF Loop DF Systems

Techniques for reducing bearing errors in vertical loop HF direction finders for ionospherically propagated signals were evaluated in a dual-channel system. A main channel provides a bearing display from the output of a rotating loop; an auxiliary channel unblanks the bearing ng display when propagation conditions are favorable for minimum bearing error. Circuitry to provide optimum unblanking for a wide variety of signal and fade conditions is described. The results of an operational evaluation are presented and show that a large majority of the unblanked bearings can be restricted to ±15° of the great-circle bearing with average bearing errors of 10° or less. Operational comparison with a contemporary system shows that the dual-channel system performance is superior with a 2 to 1 reduction ion in bearing spreads, standard deviations, and RMS error.     

Comparison of three soil-like substrate production techniques for a bioregenerative life support system

It is very important to recycle the inedible biomass of higher plants to improve the closure of bioregenerative life support system (BLSS). Processing candidate higher plant residues into the soil-like substrate (SLS) as the plant growth medium is a promising way to achieve. In this study, three different processing techniques of SLSs, using residues of wheat and rice as feedstock, were compared. As for the first traditional technique, SLS1 was obtained by successive conversion of wheat straw by oyster mushrooms and worms. In the other two methods, SLSs were produced with aerobic fermentation (SLS2) or anaerobic fermentation (SLS3) followed by worm conversion. The changes in SLS cellulose, lignin, available elements and pH were measured during the production processes. The maturity was evaluated by the value of C/N. The fertilities were compared in terms of available elements contents and lettuce productivities. The results indicated that the second technique was optimal, whose process cycle was 30 days less than that of SLS1. The total cellulose and lignin degradation of SLS2, achieved 98.6% and 93.1% during the 93-days-processing, and the lettuce productivity reached 12.0 g m⁻² day⁻¹.     

Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration

The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument was built for launch and operation on the NASA Ionospheric Connection Explorer (ICON) mission. The instrument was designed to measure thermospheric horizontal wind velocity profiles and thermospheric temperature in altitude regions between 90 km and 300 km, during day and night. For the wind measurements it uses two perpendicular fields of view pointed at the Earth’s limb, observing the Doppler shift of the atomic oxygen red and green lines at 630.0 nm and 557.7 nm wavelength. The wavelength shift is measured using field-widened, temperature compensated Doppler Asymmetric Spatial Heterodyne (DASH) spectrometers, employing low order échelle gratings operating at two different orders for the different atmospheric lines. The temperature measurement is accomplished by a multichannel photometric measurement of the spectral shape of the molecular oxygen A-band around 762 nm wavelength. For each field of view, the signals of the two oxygen lines and the A-band are detected on different regions of a single, cooled, frame transfer charge coupled device (CCD) detector. On-board calibration sources are used to periodically quantify thermal drifts, simultaneously with observing the atmosphere. The MIGHTI requirements, the resulting instrument design and the calibration are described.